Centrifugal casting machine



Oct. 8, 1929 L. T. KNocKE CENTRIFUGAL CASTING MACHINE a. 1 I .WN lv I I I I e I I I M L1 ...L14 SLI .I I I s l. I V Y nw ww Nw n QN NN QM. mw. m. s )e W. o s HI IL 2 mm. n h .HNII \N-v SA b. w f 1 n E hw n. ,ww I II d e W. I :NW QN I :I: U E S. u ww ww I N VEN TOR. 6% f M A TTORNE Y.

Wl TNESSES Ct. 8, 1929. T, KNOCKE 1,731,051

CENTHIFUGAL CASTING MACHINE Filed June 22, 1928 2 Sheets-Sheet 2 Wl TYESSES Q 0 f 4 TM" ATToRNEY.

Patented Oct. 8, v1929 UNITED STATES LOUIS T. KNOCKE, 0F DETROIT, MICHIGAN CENTRIFUGAL CASTING MACHINE Application led June 22,

This invention relates to centrifugal casting machines and has for its object to perfect details of construction of such machines for moving the mold into and out of position for receiving the metal and for operating the plunger to eject the casting from the mold and for pouring the molten metal in exactly measured quantity, timed in relation to the operation of the machine.

Another object of the invention is to perfect details of construction of the metal pouring tube whereby the metal is taken from near the bottom ofl the crucible, is measured in quantity and is delivered to the rotating mold uniformly with each operation.

Vit-h the above and other objects in view the invention consists in the centri-fugal casting machine as herein .claimed and all equivalents. Y

Referring to vthe accompanying drawings in which like characters of reference indicate the same parts in different views,

Fig. 1 is a longitudinal sectional view of a centrifugal casting machine constructed in accordance with this invention;

Fig. 2 is a plan view thereof without the furnace;

Fig. 3 is a sectional end elevation thereof on the plane of line 3--3 of Fig. 1;

Fig. 4 is an enlarged sectional detail view of the guide and air valve control for the pouring tube;

Fig. 5 is an enlarged sectional view of the parts showing the mold in position for pouring, and

Fig. 6 is a mold cap.

In these drawings, 10 indicates a base on which is mounted an electric motorll driving a tubular shaft 12 which is mounted in suitable bearings 13 and is capable of an end- Wise movement in such bearings, being splined on the motor shaft 14 to receive its drive from the motor at all times notwithstanding its longitudinal movement.

A worm shaft 15 is mounted in suitable bearings on the base and is driven from the motor 11 by a pulley 16 thereon connected by detail view of a spring for the la belt 17 with a belt pulley 18 on the motor 1928. Serial No. 287,596.

shaft, a clutch 19 being provided for establishing driving connection between the Worm shaft and its pulley 16. A worm2() on the worm shaft drives a worm wheel 21, which carries a beveled pinion 22 meshing with a beveled gear 23 on a cam shaft 24, said cam shaft being mounted in the'b'ase and carrying a cam drum 25 with a cam groove 26 in its periphery. l

Fixed on the tubular shaft 12 is a'lange 27 and threaded on the tubular shaft a short distance from the flange is a ring 28 and bel tween them are located thrust roller bearing members 29 engaged by and housed within a shifter 30, which loosely surrounds the tubular shaft and is provided with a downwardly extending stem 31 passing through a guide slot in the bearing base and terminating in a roller 32, which travels in the cam groove 26. Thus the rotation of the cam shaft from the motor causes the longitudinal reciproca- 'tion ofthe tubular shaft 12.

recess of the mold cap. The turning movement of the mold cap 38 is such as may be imparted to it b the rotating mold when in contact therewith.

A plunger 40 is contained within the tubular shaft 12 and provided with a plunger head 41 on its end fitting within the mold housing 34 and the mold body 35 and said plunger is provided with a pair of shoulders 42 and 43, between which there is loosely mounted on the plunger a grooved collar 44, Which is keyed to the tubular shaft 12 by a set vscrew 45 threaded through said tubular shaft and entering the groove of the collar. A coil spring 46-surrounds the plunger and bears at one end against shoulder 42 and at the other end against collar 44 and tends to partially withdraw the plunger head 41 kfrom the mold body 35. As the tubular shaft 12 moves forward from the position shown in Fig. 1

the first part of its movement does not effect a movement of the plunger, which is held in engagement with the end of the motor shaft 14 by the pressure of spring 46, but whencollar 44 engages shoulder 43 the plunger is compelled to move forward with the tubular shaft as said shaft advancesto bring the mold body into engagement with the mold cap 38. On the return movement the plunger moves with the shaft until the end of the motor shaft 14 is struck by the end of the plunger, whereupon the plunger vstops and the shaft continues to recede, causing the plunger to eject the casting from the mold body.

A furnace 47 is positioned as close as convenient to the mold cap 38 with its pouring trough 48 in register with the central pouring opening through the mold cap and within the furnace is a Crucible 49 containing the molten metal and having a spout registering with the pouring trough 48.

Passing through an opening in the cover of the furnace 47 is a pouring tube 50, preferably formed of graphite and vertically reciprocated to lift the molten metal and pour it in measured quantities through the spout and trough 48 into the mold. A tube head 51 is tightly fitted on the upper end of the pouring tube and works in asuitably supported iiXed guide 52, there preferably being rollers 53 on the tube head traveling in guide grooves of the guide 52. Said tube head is suspended by a cable 54 attached to it and passingthrough an opening in 'the top of the guide and around suitably supported pulleys 55 and a pulley 56 on a bracket arm on base 10 and connected with a stud 57 adjustably clamped in a radial slot 58 of a disk 59 carried on the end of cam shaft 24. Thus the pouring tube will be raised and lowered with each cycle of operation of the machine and to an extent determined by the position of the stud 57 in the slot 58.

A U-shaped cavity 60 is formed in the pouring tube 50 with its short leg opening in the direction of the pouringspout of the Crucible and its longer leg connecting with an air vent 61 passing u through the pouring tube to its upper en The packing 62 between the upper end of the pouring tube and the tube head 51 prevents communication between this air vent 61 and the atmosphere except through a valved passageway 63 inthe top of the pouring tube head 51. A springseated valve 64 controls said passageway 63 and a head member 65 on the upper end of the valve stem, against which the valve spring 66 bears, is adjustably mounted on the valve stem by a cap nut 67 to vary the degree of spring pressure with which the valve is held on its s eat. The valve will be forced open in the upper position of the pouring tube by the cap nut 67 striking the end wall of the guide 52, asl shown in Fig. 4, to admit air and permit the metal to iiow out of the pouring tube and it will also be forced open by a lever 68 when the pouringv tube is near its lowermost position to vent the cavity ofthe pouring tube and permit the molten' metal to enter said cavity. This lever 68 is pivotally mounted on the end ofthe pouring tube head 51 with one end engaging t-he head 65 of the valve stem and the other end projecting be yond the pouring tube head in position to be engaged'near the lower end of the movement of the pouring tube by a lug 69 adjustably mounted in a slot 70 of the guide 52. The lever 68 is spring-pressed by a spring 71 into engagement with the head 65 of the valve stem, but such spring pressure is not capable of overcoming the spring pressure of the valve to prevent the valve from seating.

The centrifugal casting machine of this invention is designed for continuous automatic production of small castings of such shape and quantities as to `lend themselves physically and economically to this method of production. i I

Parts such as chilled, faced cast iron tappets, spark plugshells, thrust washers, bushings, rollers, spur gears for certain uses, etc., are mentioned to indicate the class of parts that are bestadapted to this method of casting and that offer profitable possibilities.

Obviously this method of casting can be applied to numerous shapes and forms other than those mentioned above, the commercial possibilities depending upon the particular requirement of the casting.

In addition to the casting of cast iron, other metals, such as brass, aluminum, etc., can be worked readily, and glass may be equally adapatable.

The outstanding feature of this method of casting lies in the fact that it is automatic, rapid and continuous, a basic requirement for uniform quality and low production cost.

In operation the mold 35, mold shaft 12, and plunger 40, driven by the motor 1l, at a speed which may be approximately twelve hundred revolutions per minute, are moved from the position shown by the camon drum 25 and by the mold shifter 30 to the right until the rotating mold 35 contacts with. mold cap 38. The mold cap yields slightly through the springs on the side of its supporting ball bearing and rotates as one with the mold.

The plunger 40 does not move with the shaft 12 at first, but lags behind until the plunger shifter 44, which moves with the shaft, contacts with the plunger shoulder 43. Thus, thel distance between the plunger shifter 44 and shoulder 43 determines the depth of the mold cavity in the mold.

While the mold is advancing, (moving to iia the right), the pouring tube 50 is rising in the molten metal in the Crucible 49 and carrying with it a weight of metal depending on the adjustment of the air valve in the tube head 51.

After the mold has fully advanced and is in Contact with the mold cap the tube pour stop formed by cap nut 67 contacts with the top of the guide 52, thus opening the air valve and allowing the Ametal in the tube to run out of the cavityA 60 and flow down the spout and trough 48, through the mold cap and into the mold.

The mold and plunger now retreat, (move to the left) as one, the spring 46 pressing the plunger' shoulder 43 against the shifter 44. lThis positiom-obtains until the end of the plunger contacts with the end of the motor shaft, and is stopped.v` The mold shaft continues to retreat to the end of the stroke. This relative movement between the shaft and plunger forces the Casting from the mold.

Meanwhile the pouring tube with its air valve Closed has descended from the pouring position down into the molten metal in the Crucible to the position shown in the drawing. Just previous to reaching this position, the tube fill lever 68 Contacts with the trip lug 69, opening the air valve and allowing metal to refill the tube. This Completes the machine Cycle and corresponds to one revolution of the cam drum.

When the pouring tube reaches the end of the down stroke and the air relief valve is opened by the tube fill lever 68 metal rises in the cavity in the tube to the height of that 1n the cru-Cible. As the tube rises the air valve Closes and the level of the metal in the tube is raised above that in the Crucible, creating a partial vacuum in the tube cavity above the metal. As the tube continues to rise the vacuum increases until it exceeds a predetermined value, for which the air valve spring is set, when lthe air relief valve opens and allows a portion of the metal to flow back into the Crucible, thus definitely determining the amount of metal remaining and fixing the quantity of metal discharged in each operation. By taking the metal from the bottom of the Crucible and by lmaintaining a deoXidizing flame in the furnace and mold cap, the metal delivered to the mold will be in an exceptionally clean condition.

The Crucible furnace is considered as a means for maintaining the molten metal at a required temperature rather than a place for melting it and the supply of molten metal may be replenished inthe Crucible at intervals in any suitable manner.

What I Claim as new and desire to secure by Letters Patent is:

1. A centrifugal casting machine comprising a rotatably mounted'mold cap, a slidably mounted motor-driven tubular shaft, a mold body on the shaft, means for sliding the shaft to cause the mold body to fit the mold Cap, a

plunger fitting within the tubular shaft for' .ej ecting castings fronthe mold body, and means for causing rela ive movement between the plunger and the tubular shaft.

2. A centrifugal Casting machine comprising a rotatably mounted mold Cap, a motordriven member, a slidably mounted tubular shaft splined on the mieter-driven member, means for sliding the tubular shaft on the motor-driven member, a mold body Carried by the tubular shaft movable into engagement with the mold cap, a plunger within the tubular shaft for ejecting castings from the mold body,l shoulders on said plunger, a Collar loosely mounted on the plunger between the shoulders and keyed to the tubular shaft to move therewith, andacoiled spring surrounding the plunger andbearing on one shoulder and on the sleeve and tending to hold the other shoulder in engagement with the sleeve, said plunger engaging the motor-driven member to cause relative movement between the tubular shaft and the plunger.

3. A centrifugal Casting machine comprising a base, a mold cap rotatably mounted on the base, a motor on the base, a tubular shaft slidably mounted in bearings on the base and splined on the motor shaft, a mold memberI on the tubular shaft to fit the mold cap, a cam drum driven by the motor, a shifter on the tubular shaft engaging the Cam drum for sliding the tubular shaft in its bearings, a plunger within the shaft for ejecting castings from the mold member, andmeans for causing J5 passageway therethrough, a rotated mold` I mounted to advance into contact with the mold cap, a furnace having a funnel-shaped fill trough registering with and positioned Close to the opening in the mold cap, a crucible within the furnace, and a vertically reciprocating pouring tube for lifting molten metal from the Crucible and discharging throulgh the trough into the mold cap.

6. n a centrifugal casting machine, a rotating mold, a mold Cap adapted to be Contacted by the mold and provided with a central passageway, a furnace having a funnelshaped pouring trough registering with and positioned Close to the opening in the mold cap, a Crucible within the furnace, and a vertically reciprocating pouring tube havin an automatic-ally vented Cavity to receive mo ten metal from the 'Crucible and vdischarge it through the pouring trough to the passagewayof the mold cap.

7. A vertically reciprocating pouring tube for casting lmachines comprising a guide, a head member mounted therein, a tube member fit-ting in the head member and containing a cavity with an orifice at one side of the tube member and a vent leading Jfrom said cavity to the upper end of the tube member, a spring-seated valve in the head member controlling the vent, means for opening said valve near the upper position of the pouring tube, and means for opening said valve near the lower position of the pouring tube.

8. A vertically reciprocating pouring tube for casting machines comprising a head member, a guide therefor, operating means connected with the head member, a tube member mounted in the head member and having a vented cavity, a spring-pressed valve on the head member for controlling the Vent,

said valve being adapted to engage the upper end of the `guide in the upper position of the pouring tube for opening the vent, a

lever on the head member engaging the valve,

and an adjustable trip member engaged by the lever for opening the valve in a lower position of the pouring tube.

9. A vertically reciprocating pouring tube for metal casting machines comprising a guide having guide grooves, a head member fitting within the guide and having rollers traveling in the guide grooves, a tube member fitting within the head member and having airtight connection therewith and provided with a vented cavity, a spring-pressed 35 valve in the head member controlling the vent, aeable 'connected with the head member, means for operating the cable to lift the head member in the guide, said valve engaging the end of the guide to open the vent in 40 the upper position of the pouring tube, a

lever on the head member engaging the valve, and an adjustable trip member on the guide engaging the lever in a lower position of the head member to open the valve.

10. A centrifugal casting machine comprising a rotatably mounted yielding mold cap, a slidably mounted motor-driven shaft, a mold body on the shaft, and means for sliding the shaft to cause the mold body to fit the yielding mold cap.

In testimony whereof, aHiX my signature. i LOUIS T. KNOCKE. 

